Source : Webster's Revised Unabridged Dictionary (1913)

Incantation \In`can*ta"tion\, n. [L. incantatio, fr. incantare
   to chant a magic formula over one: cf. F. incantation. See
   {Enchant}.]
   1. The act or process of using formulas sung or spoken, with
      occult ceremonies, for the purpose of raising spirits,
      producing enchantment, or affecting other magical results;
      enchantment. ``Mysterious ceremony and incantation.''
      --Burke.

   2. A formula of words used as above.

Source : WordNet®

incantation
     n : a ritual recitation of words or sounds believed to have a
         magical effect [syn: {conjuration}]

Source : Free On-Line Dictionary of Computing

incantation
     
        Any particularly arbitrary or obscure command that one must
        mutter at a system to attain a desired result.  Not used of
        passwords or other explicit security features.  Especially
        used of tricks that are so poorly documented that they must be
        learned from a {wizard}.  "This compiler normally locates
        initialised data in the data segment, but if you {mutter} the
        right incantation they will be forced into text space."